The investigation of the parameters affecting the ZnO nanoparticle cytotoxicity behaviour: A tutorial review

In the last 30 years the research about zinc oxide nanoparticles (ZnO NPs) and their related toxicity has shown a boom. ZnO NPs show cytotoxicity for both prokaryotic and eukaryotic cells and many studies demonstrated their selective toxicity towards cancer cells. However, with the increasing number of publications, it is observed an increase in the discrepancies obtained between the various results. Soon the scientific community understood that the ZnO NC toxicity behaviour is affected by many factors, related not only to the ZnO NPs themselves, but also to the experimental conditions used. Many recent reviews discussed these parameters by reporting experimental evidence and tried to assess the general statements about the ZnO NP cytotoxicity. This information is extremely useful for the evaluation of which type of ZnO NPs is more or less suitable for a specific study or application. However, despite that, a deep comprehension of the ZnO NP behaviour in relation to the different experimental conditions is still lacking. Actually, a full understanding of the reasons behind the NP behaviour is essential to better assess their biological activity and in particular their therapeutic application, avoiding undesired effects both in the experimental and clinical contexts. This tutorial review aims to be an experimental and practical guide for scientists that faced with the use of ZnO NPs for biomedical applications and, in particular, for their therapeutic purposes. The driving idea is to not simply summarize the results reported in the literature, but to provide instruments for a deep comprehension of the mechanisms affecting the ZnO NP cytotoxicity and behavior. This review also aims to point out the critical experimental parameters to be considered when working with these NPs, as well as the main related risks and limitations that scientists have to face

Evs and bioengineering: From cellular products to engineered nanomachines

Extracellular vesicles (EVs) are natural carriers produced by many different cell types that have a plethora of functions and roles that are still under discovery. This review aims to be a compendium on the current advancement in terms of EV modifications and re-engineering, as well as their potential use in nanomedicine. In particular, the latest advancements on artificial EVs are discussed, with these being the frontier of nanomedicine-based therapeutics. The first part of this review gives an overview of the EVs naturally produced by cells and their extraction methods, focusing on the possibility to use them to carry desired cargo. The main issues for the production of the EV-based carriers are addressed, and several examples of the techniques used to upload the cargo are provided. The second part focuses on the engineered EVs, obtained through surface modification, both using direct and indirect methods, i.e., engineering of the parental cells. Several examples of the current literature are proposed to show the broad variety of engineered EVs produced thus far. In particular, we also report the possibility to engineer the parental cells to produce cargo-loaded EVs or EVs displaying specific surface markers. The third and last part focuses on the most recent advancements based on synthetic and chimeric EVs and the methods for their production. Both top-down or bottom-up techniques are analyzed, with many examples of applications

Extracellular vesicles and their current role in cancer immunotherapy

Extracellular vesicles (EVs) are natural particles formed by the lipid bilayer and released from almost all cell types to the extracellular environment both under physiological conditions and in presence of a disease. EVs are involved in many biological processes including intercellular communication, acting as natural carriers in the transfer of various biomolecules such as DNA, various RNA types, proteins and different phospholipids. Thanks to their transfer and targeting abilities, they can be employed in drug and gene delivery and have been proposed for the treatment of different diseases, including cancer. Recently, the use of EVs as biological carriers has also been extended to cancer immunotherapy. This new technique of cancer treatment involves the use of EVs to transport molecules capable of triggering an immune response to damage cancer cells. Several studies have analyzed the possibility of using EVs in new cancer vaccines, which represent a particular form of immunotherapy. In the literature there are only few publications that systematically group and collectively discuss these studies. Therefore, the purpose of this review is to illustrate and give a partial reorganization to what has been produced in the literature so far. We provide basic notions on cancer immunotherapy and describe some clinical trials in which therapeutic cancer vaccines are tested. We thus focus attention on the potential of EV-based therapeutic vaccines in the treatment of cancer patients, overviewing the clinically relevant trials, completed or still in progress, which open up new perspectives in the fight against cancer

The shielding effect of phospholipidic bilayers on zinc oxide nanocrystals for biomedical applications

Zinc oxide nanocrystals (ZnO NCs), thanks to their unique properties, are receiving much attention for their use in nanomedicine, in particular for therapy against cancer [1]. To be efficiently employed as diagnostic and therapeutic (yet theranostic) tools [2], highly dispersed, stable and non-toxic nanoparticles are required. In the case of ZnO NCs, there is still a lack of knowledge about cytotoxicity mechanisms and stability in the biological context, as well as immunological response and haemocompatible features. Most of these above-mentioned behaviours strongly depends on physico-chemical and surface properties of the nanoparticles. We thus propose a novel approach to stabilize the ZnO NCs in various biological media, focusing on NC aggregation and biodegradation as a function of the surface functionalization. We synthesized bare ZnO NCs, amino-propyl functionalized ones, and lipid bilayer-shielded NCs, and we characterized their morphological, chemical and physical properties. The stability behavior of the three different samples was evaluated, comparing their biodegradation profiles in different media, i.e. organic solvents, water, and different simulated and biological fluids. The studies aim to investigate how the particle surface functionalizations, and thus chemistry and charge, could influence their hydrodynamic size, zeta potential and consequent aggregation and degradation in the different solvents. We demonstrated that bare and amino-functionalized ZnO NCs strongly and rapidly aggregate when suspended in both simulated and biological media. Long-term biodegradation analysis showed small dissolution into potentially cytotoxic Zn-cations, also slightly affecting their crystalline structure. In contrast, high colloidal stability and integrity was retained for lipid-shielded ZnO NCs in all media, rendering them the ideal candidates for further theranostic applications [3]. [1] P. Zhu, Z. Weng, X. Li, X. Liu, S. Wu Adv. Mater. Interfaces 3 (2016) 1500494. [2] E. Lim, T. Kim, S. Paik, S. Haam, Y. Huh, and K. Lee, Chem. Rev. 115 (2015) 327−394. [3] B. Dumontel, M. Canta, H. Engelke, A. Chiodoni, L. Racca, A. Ancona, T. Limongi, G. Canavese and V. Cauda, J. Mater. Chem. B, under review The support from ERC Starting Grant – Project N. 678151 “Trojananohorse” and Compagnia di Sanpaolo are gratefully acknowledged

Microwave-assisted methacrylation of chitosan for 3D printable hydrogels in tissue engineering

Light processable natural polymers are highly attractive for 3D printing of biomedical hydrogels with defined geometries and sizes. However, functionalization with photo-curable groups, such as methacrylate or acrylate groups, is required. Here, we investigated a microwave-assisted process for methacrylation of chitosan to replace conventional methacrylation processes that can be time consuming and tedious. The microwave-assisted methacrylation reaction was optimized by varying the synthesis parameters such as the molar ratio of chitosan to the methacrylic agent, the launch and reaction times and process temperature. The optimized process was fast and efficient and allowed tuning of the degree of substitution and thereby the final hydrogel properties. The successful methacrylation and degree of substitution were verified by H-1 NMR and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The influence of the degree of methacrylation on photo-rheology, mechanical stiffness, swelling degree and gel content was evaluated. Furthermore, favourable 3D printability, enzymatic degradability, biocompatibility, cell migration and proliferation were demonstrated giving promise for further applications in tissue engineering

Effects of Cognitive Remediation on Cognition, Metacognition, and Social Cognition in Patients With Schizophrenia

We aimed to evaluate in a sample of outpatients with schizophrenia (SCZ) the effectiveness of a cognitive remediation (CR) program (through the use of the Cogpack software) [computer-assisted CR (CACR)] in addition to standard therapy on cognitive outcomes as compared with that in a control active group (CAG) and to highlight a possible effect on social cognition (SC), metacognition, symptomatology, and real-world functioning. Of the 66 subjects enrolled, 33 were allocated to CACR and 33 to the CAG. Twenty-three patients in the CACR group and 25 subjects in the CAG completed at least 80% of the 48 prescribed CACR sessions, performed twice a week, for a total of 24 weeks of treatment. A significant time × group interaction was evident, suggesting that patients undergoing CACR intervention improved in specific metacognitive sub-functions (understanding others' mind and mastery), some cognitive domains (verbal learning processing speed, visual learning, reasoning, and problem solving) (h(2) = 0.126), depressive symptoms, SC, awareness of symptoms, and real-world functioning domains (community activities and interpersonal relationships) more significantly than did patients undergoing CAG. The most noticeable differential improvement between the two groups was detected in two metacognitive sub-functions (understanding others' mind and mastery), in verbal learning, in interpersonal relationship, and in depressive symptomatology, achieving large effect sizes. These are encouraging findings in support of the possible integration of CACR in rehabilitation practice in the Italian mental health services

Biomimetic Non-Immunogenic Nanoassembly for the Antitumor Therapy

Nanoassembly (1) for inducing apoptosis in cancer cells comprising: a core (2) comprising at least a nanoparticle of a nano structured and semiconductor metal oxide, said nanoparticle being monocrystalline or polycrystalline; a shell (3) formed by a double phospholipid layer and proteins derived from an extracellular biovesicole chosen between an exosome, an ectosome, a connectosome, an oncosome and an apoptotic body, and an oncosome, said core (2) being enclosed inside said shell (3); and a plurality of targeting molecules (4, 4', 4") of said cancer cells, preferably monoclonal antibodies (4, 4', 4"), said molecules (4, 4', 4") being anchored to the external surface of said biovesicole

Aspects Contributing to the Underemployment of the Top 3 Fields of Engineering in Las Piñas City, and Muntinlupa City

Up to this day, underemployment continuously becomes a significant contributor to poverty, and it happen to any other industry, including the engineering industry. As an attempt to contribute to the body of knowledge regarding underemployment, this study investigated the leading causes of underemployment in engineers at Las Piñas City and Muntinlupa City. The study used an online survey questionnaire with non-probability sampling to collect the necessary data from various licensed engineers. Descriptive statistics was the data analysis method of the study. The results indicate that the leading causes of underemployment in different engineering fields are lack of experience, limited job opportunities, many competitions, and the substandard education system. Mechanical Engineering, Electronics Engineering, and Electrical Engineering are the top three engineering fields that often experience underemployment. The study concluded that experience is highly needed to attain employment in the engineering industry

3D printable acrylate polydimethylsiloxane resins for cell culture and drug testing

Nowadays, most of the microfluidic devices for biological applications are fabricated with only few well-established materials. Among these, polydimethylsiloxane (PDMS) is the most used and known. However, it has many limitations, like the operator dependent and time-consuming manufacturing technique and the high molecule retention. TEGORad or Acrylate PDMS is an acrylate polydimethylsiloxane copolymer that can be 3D printed through Digital Light Processing (DLP), a technology that can boast reduction of waste products and the possibility of low cost and rapid manufacturing of complex components. Here, we developed 3D printed Acrylate PDMS-based devices for cell culture and drug testing. Our in vitro study shows that Acrylate PDMS can sustain cell growth of lung and skin epithelium, both of great interest for in vitro drug testing, without causing any genotoxic effect. Moreover, flow experiments with a drug-like solution (Rhodamine 6G) show that Acrylate PDMS drug retention is negligible unlike the high signal shown by PDMS. In conclusion, the study demonstrates that this acrylate resin can be an excellent alternative to PDMS to design stretchable platforms for cell culture and drug testing